Author Topic: Piggott Blades simplification possible?  (Read 38722 times)

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Janne

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Re: Piggott Blades simplification possible?
« Reply #30 on: April 03, 2012, 08:24:31 AM »
Hi,

This method sure looks interesting. I'm going to need to make one new blade set this spring, and originally I though of using the "traditional" chainsaw method for those.. But this thing looks even easier I think.

For the side of the blade facing away from the wind, mayby it could be rough-cut with a chainsaw manually before starting with the planer, to reduce the amount that needs to be shaved off? I did that with my last blade set, keep the chain speed high and keep the cutting bar moving (sideways..) and I actually had quite a good control over it.

I think electric saw is better for this job, it does not have as much power as a gas powered one, but it's lighter and much nicer to use especially if working indoors. That's what I've used before for roughing up blades.

Has anyone experimented about how to best file the chain for this kind of job? I think I read from somewhere, that for cutting along the direction of the grain, it would be best to have a worn out chain (so the rake is quite close in height to the cutting teeth), and reduce the cutting teeth angle to 15degrees for best results..? I think I'd best try a few settings before actually cutting my precious blanks :)
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breezyears

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Re: Piggott Blades simplification possible?
« Reply #31 on: April 03, 2012, 09:42:44 AM »
You can get a "ripping" chain... less teeth.

Menelaos

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Re: Piggott Blades simplification possible?
« Reply #32 on: April 03, 2012, 12:05:43 PM »
For the side of the blade facing away from the wind, mayby it could be rough-cut with a chainsaw manually before starting with the planer, to reduce the amount that needs to be shaved off?

The side faciong away is not touched at all as this is on the bottom of the wood piece over all the length(!!!)

Actually a chainsaw is not even needed, it works great with a band saw as well...Today I made a complete set of 10 foot diameter prop in only 3 hours...all I need is 3 cuts with the band saw. The first one is to get the shape of the blade as usual (from root to tip on the trailling edge). I the put the marks as explained in my previous post. I then use the band saw to cut the thickness of the blade from the leading edge. This cut then is smoothed a bit as it will be reference for cut number 3.
Cut number 3 will give me the windward side with the twist. I Put a flat peace of wood (about 2mm high) next to the band of the saw to have a guide and then cut along the drop line of the trailling edge with the blade standing on the leading edge.
Those 3 steps take about 20 minutes for all three blades. I then take the power sander to get the windward side finished and form out the root section to whatever ones Eye likes. After that I turn around and make the lee side which is fairly quick work with the power sander....really fast, no jig needed, no chainsaw needed...but still I want to try that chainsaw thing and have ordered an electric one  ;)

Maybe its a good idea to make a video clip of the whole process...

Janne

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Re: Piggott Blades simplification possible?
« Reply #33 on: April 03, 2012, 12:13:21 PM »

The side faciong away is not touched at all as this is on the bottom of the wood piece over all the length(!!!)


Hi Max,

What I meant, is to first rough cut the trailing edge with a chainsaw (from the high point of the profile, to the trailing edge) to reduce the need for power planer time. But now thinking it again, the amount of wood removed from there is quite small, so it might not make much sense to put the chainsaw to work in there.

For the side facing the wind, I'll have to go with the chainsaw, as I don't have a band saw big enough to cut it :)

For some reason the ripping chain does not sound too good, as the goal is to make a cut as clean as possible, to reduce the need for sanding.
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Menelaos

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Re: Piggott Blades simplification possible?
« Reply #34 on: April 03, 2012, 12:21:03 PM »
there really is only little material to take off from the lee-side, nearly nothing up to half way from the root of the blade...at least for the trailling edge...its really not worth it making this with a chainsaw. If you want it quicker, I would use the power planer but for my small 10 foot blade set I used a manual planer for that and the did the fine tuning with the power sander and later by hand.

This whole method of course only works out accurately if the Lee seide of the untached wood is absolutely even. For this I do have a surface planing machnineso that I can get it nice and even and the right thickness...

Menelaos

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Re: Piggott Blades simplification possible?
« Reply #35 on: April 04, 2012, 12:45:00 PM »
Ok...I did make a video but it still needs to be cut and in some parts I had my hand on the microphone so that needs fix as well... After easter I will post it here and I hope you will like it...

Max

Menelaos

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Re: Piggott Blades simplification possible?
« Reply #36 on: April 05, 2012, 09:14:39 PM »
Well, here is the video:

http://www.youtube.com/watch?v=tK-83KUKC8w&feature=youtu.be

It didn't turn out well and I will make a new one somewhen but for now it' ok ;-)
Its hard to to stuff and explain things in a foreign language the same time, so please do not kill me for my english !

When my chainsaw arrives I will make a jig and see how that works out ...

Max
« Last Edit: April 05, 2012, 10:01:40 PM by Menelaos »

gizmo

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Re: Piggott Blades simplification possible?
« Reply #37 on: April 05, 2012, 09:30:16 PM »
I got a "This video has been removed because it is too long. "

Glenn

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Re: Piggott Blades simplification possible?
« Reply #38 on: April 05, 2012, 09:31:13 PM »
oh sh...I will see what I can do about that....took me 2 hours to upload it...

Menelaos

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Re: Piggott Blades simplification possible?
« Reply #39 on: April 05, 2012, 10:02:25 PM »
Ok, I started a new upload and changed the link in my previous post, should work in about an hour.
That video is 27 minutes long so I had to do some activation on my account first to be able to get more than 15 minutes uploaded...

Max
« Last Edit: April 05, 2012, 10:05:01 PM by Menelaos »

gizmo

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Re: Piggott Blades simplification possible?
« Reply #40 on: April 06, 2012, 12:45:20 AM »
I thinks its very good Max  :)

Thats a scary bandsaw you have there!

It should be fairly straight foward to modify Oz's chainsaw method to use your idea Max, and that would mean only one cut.

Well done.

Glenn

Menelaos

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Re: Piggott Blades simplification possible?
« Reply #41 on: April 06, 2012, 12:56:59 AM »
Yeah, that band saw is a monster. It was built in 1922 and has a weight of 2 tons....equiped with a 5 KW motor and if you switsch from star to delta too early it will kick all the fuses in the workshop :-(

With a chain saw and only one cut needed this could be a good way of beating the time world record in blade carving ;-)
« Last Edit: April 06, 2012, 01:02:18 AM by Menelaos »

southpaw

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Re: Piggott Blades simplification possible?
« Reply #42 on: April 06, 2012, 07:38:38 AM »
If a picture is worth a thousand words, this video is worth a million.
Good job, Thanks for posting it.
It makes blade carving seem much more possible for someone who was always hesitant to try.

jlt

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Re: Piggott Blades simplification possible?
« Reply #43 on: April 06, 2012, 08:40:40 AM »
  That's a great video.
     After watching it I got a brain fart, how about mounting a electric chain saw from underneath a table with blade sticking straight up. Sort of a redneck   band saw.

                                       JLT

JeffD

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Re: Piggott Blades simplification possible?
« Reply #44 on: April 06, 2012, 10:45:39 AM »
I've been carving blades using Hugh's method for about five years now so I was sceptical about how much easier and quicker this method is.  After watching the video I built a set of 3 blades this morning for a new 1m turbine I'm working on and wow, I'm a convert now.  I had been using a band saw for rough cutting my blades before but some cuts were tricky and really slowed down the process.  With your method the cutting process is now a lot easier and definitely quicker. 

The lay of the blade is different to what I am use to so looks strange.  Will be another two weeks before I get this turbine up in the air and connected to the data logger to see how well the new blades perform.

Thanks for sharing your work and making the video.  I agree too that in the video you did a great job at explaining your method, no need to redo it.

Menelaos

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Re: Piggott Blades simplification possible?
« Reply #45 on: April 06, 2012, 02:44:22 PM »
Thanks!

@ jlt:

That came to my mind as well but I guess that it will be quite difficult to handle as the chainsaw blade is really thick...but I didn't try it. I feel that if you want to get it accurate with a chain saw, using a jig is the best way of doing it as you have to points to guide the chain saw blade with some preassure...
The advantage on teh other side would be that building an "band saw" this way would be really cheap if you consider that you then can cur really thick blocks of would where cheap band saws can only do a few centimeters.
Another problem might be that the chain saw blade is really wide. This might be good for straight cuts but for getting angles it will be difficult. Furthermore with my method you will have to cut "up hill". What will then happen with the back side of the chainsaw blade, will it damage the wood that is left? I cannot tell as I have never used a chain saw in my life befor...  ::)


@ Jeff:

The blades will perform the same if you used the same angles and dimensions. Basically nothing changes to the airfoil or the stations....but anyway I did not expect someone would try it only a few hours after I put the video online and I am happy that you can confirm that it makes things easier :-)
Would be nice if you can post your results here!


Max
« Last Edit: April 06, 2012, 02:58:15 PM by Menelaos »

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Re: Piggott Blades simplification possible?
« Reply #46 on: April 06, 2012, 05:06:22 PM »
I've spent a lot of time running a chain saw, the chainsaw/bandsaw would scare the F out of me, that would be an imminent castastrophic injury waiting to happen.
"Here hold my beer and watch me saw my arm off"
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Re: Piggott Blades simplification possible?
« Reply #47 on: April 06, 2012, 07:55:55 PM »
Menelaos, very nicely done and great video.  Thank you for you for your time.

Menelaos

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Re: Piggott Blades simplification possible?
« Reply #48 on: April 07, 2012, 01:12:26 PM »
this discussion bord is all about sharing, ricght? ;-)

DamonHD

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Re: Piggott Blades simplification possible?
« Reply #49 on: April 07, 2012, 03:14:30 PM »
Absolutely right.

Rgds

Damon

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Re: Piggott Blades simplification possible?
« Reply #50 on: April 08, 2012, 05:08:44 PM »
it would actually be nice to hear how Hugh feels about that...

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Re: Piggott Blades simplification possible?
« Reply #51 on: April 08, 2012, 05:23:30 PM »
it would actually be nice to hear how Hugh feels about that...

You may send him a pm with a link to this thread.  His user name here is scoraigwind

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Re: Piggott Blades simplification possible?
« Reply #52 on: April 08, 2012, 06:50:07 PM »
it would actually be nice to hear how Hugh feels about that...

Max, if you put these blades on a machine and it performs as expected, to put it bluntly with NO disrespect intended what does it matter what Hugh thinks?

FAB , I knew what you meant, but wasn't where I could fix it , fat fingers & small keyboard on phone :(
Bruce S
« Last Edit: April 09, 2012, 09:37:49 AM by Bruce S »
I aint skeerd of nuthin.......Holy Crap! What was that!!!!!
11 Miles east of Lake Michigan, Ottawa County, Robinson township, (home of the defacto residential wind ban) Michigan, USA.

Menelaos

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Re: Piggott Blades simplification possible?
« Reply #53 on: April 09, 2012, 08:41:14 AM »
just because I want to let him know as my idea developed from the plans in his book. He gives those workshops around europe and he writes those books on how to do stuff and I am sure he does not mind knowing about different ways of approach and mybe adapting it...

I am not sure if I got the meaning of that last sentence right...but to make it clear: this has nothing to do with disrespect. I do not want to walk around telling everybody how great my style of doing it is and how much all the other methods suck...
I just want to share the solutions that I have found to make things the way that I feel is a lot more easy and accurate and as Hugh has a lot of experience in blade carving and I like what he is doing over there, I feel he should be updated on things like this...

Max
« Last Edit: April 09, 2012, 08:43:22 AM by Menelaos »

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Re: Piggott Blades simplification possible?
« Reply #54 on: April 09, 2012, 09:08:06 AM »
Fair enough.
I aint skeerd of nuthin.......Holy Crap! What was that!!!!!
11 Miles east of Lake Michigan, Ottawa County, Robinson township, (home of the defacto residential wind ban) Michigan, USA.

fabricator

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Re: Piggott Blades simplification possible?
« Reply #55 on: April 09, 2012, 09:09:53 AM »
it would actually be nice to hear how Hugh feels about that...

Max, if you put these blades on a machine and it performs as expected, to put it bluntly with NO disrespect intended what does it matter what Hugh thinks?

Had to change that a little, I forgot the "NO"
I aint skeerd of nuthin.......Holy Crap! What was that!!!!!
11 Miles east of Lake Michigan, Ottawa County, Robinson township, (home of the defacto residential wind ban) Michigan, USA.

Menelaos

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Re: Piggott Blades simplification possible?
« Reply #56 on: April 12, 2012, 09:30:02 AM »
ok, that makes sense now :-)

Menelaos

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Re: Piggott Blades simplification possible?
« Reply #57 on: April 19, 2012, 12:36:54 PM »
hi guys,

It is probably a little early...but has anybody already tried to copy my approach of making blades?...it would be nice to get feedback on the procedure and of course on the results :-)

Max

scoraigwind

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Re: Piggott Blades simplification possible?
« Reply #58 on: May 20, 2012, 01:45:31 AM »
Hi guys,

Sorry for not replying sooner, but I don't get around to looking at this board very often.  I am kept very busy with emails.  Next time maybe somebody could send me an email and I will check in.

I agree that this is a simpler way to do it.  Dan also uses this method I believe.  He doesn't seem to read this board much either...

I do have a reason why I do it the way I do and I am not sure it's a good enough reason but I will explain it anyway.  I like to make the airfoil from a rectangular section of wood where the back is parallel to the front.  That way I know that the thickest part at 30% is actually the thickest part.  If the back is angled, and the 30% line thickness is a certain value, then this cannot also be the thickest point on the back.  In my way of thinking it can only be the thickest point if it is also parallel to the front, windward face.  I don't like any sort of corner at the thickest point, it should just be the top of a very gradual curve and as such it must be parallel to the front face.

So that's my logic.  It seems to me that the main saving in the 'Menelaus' system is that you don't have to measure and mark so much.  In the end you do have to cut off the same amount of wood and you do have to make two finished faces.   I know that all sorts of shapes work well, and I have seen blade sections that look awful to me and fly OK.  I don't have any objection to people making blades in any way that works for them and I personally do make changes to my blade carving procedure so as to make life easier at times.  I will think about modifying my instructions to reduce the number of stages and the amount of measurements that need to be made.  I am not convinced it would save me much time as I am pretty quick at doing it my way but of course a simpler way is quicker to learn.

Thanks for sharing ideas!

Hugh
Hugh Piggott scoraigwind.co.uk

scoraigwind

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Re: Piggott Blades simplification possible?
« Reply #59 on: May 20, 2012, 01:42:17 PM »
OK now I have watched the video I have a couple of other comments.

Nice work!  It's a quick way to make the blades.  I wouldn't enjoy doing it that way very much, but I appreciate that the pleasure of using sharp tools without noise and dust is not everyone's priority.  The use of the bandsaw is very ingenious.  It seems to grunt a bit at times when the twist gets tight, but Max knows how to drive it.  He doesnt' seem to use a plane and hardly uses a drawknife but maybe he tried that already and found it too slow.

I do have some worries about the 'thickness'.  The thickness gets marked at the leading edge but then a reduced thickness gets marked at the trailing edge so there is a tapered shape where the back or 'lee' side is going to be a bit sloping relative to the windward or front side.  So you lose some thickness (especially at the inner end).  You also end up with an angled face at the 'thickest point" which as I pointed out in the last message is not going to be the thickest any more unless it is parallel to the front.

I am probably nitpicking here, but suggest you might want to add a bit of thickness if you want the blades to be as strong as I like to make them.  Other than that I can't fault the resultant shape.  What works for you is fine by me.  I put the video on my blog at http://scoraigwind.co.uk/2012/05/making-wooden-blades-with-max/.  Thanks again!
Hugh Piggott scoraigwind.co.uk